The brain is located in the skull and part of the central nervous system which functions as a control center of the body in all vertebrates. The development of the brain starts with the closing of the neural tube. On the cranial end of the neural tube, 3 brain vesicles start to develope. The wall of the neural tube is built by undifferentiated neural epithelium. The cells of the neural epithelium divide and built two new cell types: the neural cells, the so called neuroblasts and the glioma (supporting cells of the neural tube). The neuroblasts form the motoric neurons of the anterior column and the sensory neurons of the posterior column. Then, there is a progressive entrance of the neuroblasts into the mantle zone and a ventral and dorsal thickning occurs: the motoric basal plate and the sensory alar plate. Inbetween there is the sulcus limitans which provides neurons of the vegetative system. Between both alar plates there is the roof plate and between the basal plates there is the floor plate. The basal and alar plate are surrounded by the marginal zone.As soon as the development of the neuroblasts is finished, the glioma start to arise. They grow into the mantle zone and differentiate into protoplasmatic and fibrillar astrocytes.
